1. Field of the Invention
This invention relates to connectors for medical electrode-bearing leads.
2. Prior Art
It is well known that more efficacious electrical stimulation of certain portions of the body may be obtained by using multiple electrode leads. Various combinations of electrodes may then be used for stimulating different portions of the body.
One example of this type of stimulation involves a four-electrode lead which is inserted in the epidural space adjoining the spinal column. In the past, spinal leads were inserted in place and then stimulated transcutaneously until the proper location was found. Once a lead was implanted, there was no possibility of changing the location of stimulation. With a multielectrode lead, the location can be altered. One type of lead used in such assemblies is the Medtronic.RTM. PISCES-QUAD.RTM. epidural lead which employs four cylindrical barrel electrodes spaced along the lead.
A female connector for pacemaker leads is illustrated in U.S. Pat. No. 4,236,525 to Sluetz et al, issued Dec. 2, 1980, in which the polarity of the two distal electrodes is reversed by repositioning the lead within the female connector assembly. In this design, both contacts in the female portion are always both used. The system allows for selecting two of the three contacts on the male lead to reverse polarity of two stimulating electrodes.
While this allows altering of polarity, it does not allow choice of electrodes through a programming system. What is needed is means to combine multiple electrodes in the available combinations and permutations. A connector is needed to connect four-electrode leads with two-conductor stimulators.